When assembling a module in which a power device, a MEMS structural body, or the like using a wide band gap semiconductor such as gallium nitride (GaN) is airtightly sealed, a method of bonding a ceramic substrate to a substrate having the power device, the MEMS structural body, or the like formed thereon, and sealing such a device therein is adopted.
For example, Japanese Patent Laying-Open No. 2013-30759 describes a packaged device formed by bonding a device substrate having an electronic circuit, a MEMS, and other devices mounted thereon to a package material provided with a via wire and having a cavity. The above publication also describes that anodic bonding or the like can be adopted as a bonding method.
Further, Japanese Patent Laying-Open No. 2010-37165 describes an anodically bonded body formed by anodically bonding a low temperature co-fired ceramic substrate to a silicon substrate.